1. Field of the Invention
The invention relates to an information recording apparatus which records information on a recording medium having a user data area and a spare area, and also relates to an information recording method, a program for recording information, a memory medium having the information recording program stored thereon, and an information recording system.
2. Description of the Related Art
The Mt. Rainier standard has been proposed as a format which adds a defect management function to the rewritable CD disk or the DVD disk. The Mt. Rainier standard offers a format which provides compatibility with the original record format of the CD-RW disk and the DVD+RW disk that are rerecordable while newly adding a defective management function.
In the following, a description will be given of the features of the Mt. Rainier standard.
(1) First Feature
The Mt. Rainier standard is characterized in that a defect management area and a spare area are positioned within the user data area of the conventional format.
Specifically, the defect management area resides both in a main table area (hereinafter referred to as an MTA) within the lead-in zone and in a secondary table area (hereinafter referred to as an STA) provided in the user data area of the conventional format.
Reallocated data are recorded on the spare area (hereinafter referred to as an SA) provided in the user data area of the conventional format.
With this provision, spare sectors are properly read by use of a particular driver (hereinafter called an MRW driver) even when a disk recorded by the Mt. Rainier format is inserted into a drive that does not support the Mr. Rainier standard (such a drive will hereinafter be referred to as conventional drive). This is because the defect management area and the spare area exist in the user data area, which is accessible by the conventional drive.
For example, a DVD+MRW disk, which is a DVD+RW disk recorded by the Mt. Rainier format, may be inserted into a conventional drive. Since the DVD+MRW disk is compatible with the conventional DVD+RW standard, the conventional drive detects the insertion of the DVD+RW disk, and reports this to a user. In response to the report that a DVD+RW disk has been inserted, a MRW driver reads a predetermined address in the disk to find that a DVD+MRW disk is actually inserted. This is because the Mt. Rainier standard prescribes that information indicative of the Mt. Rainier disk be recorded at the predetermined address in the user data area. Upon finding that the DVD+MRW disk is inserted, the MRW driver reads the defect management area recorded at a predetermined position within the user data area, thereby obtaining information about spare sectors.
The spare area also resides in the user data area. In response to a data-read request from the user, the MRW driver identifies a relevant spare area based on the defect management information if the data-read request includes a request for access to a defect area, and requests the conventional drive to read the relevant spare area. In this manner, the conventional drive can properly read the DVD+MRW disk that contains spare sectors. If the drive supports the DVD+MRW format (such a drive will hereinafter be referred to as an MRW drive), it can properly read spare sectors without the use of such MRW driver as described above.
The difference between DVD+MRW and CD-MRW, which is the Mt. Rainier standard for CD-RW, is in the arrangement of SAs. Both CD-MRW and DVD+MRW have their spare areas in the user data area. While CD-MRW has its spare areas dispersed in the user data area, DVD+MRW has its spare areas concentrated in the innermost circumference and the outermost circumference of the user data area. An SA in the innermost circumference of the user data area is referred to as an SA1, and an SA in the outermost circumference is referred to as an SA2.
(2) Second Feature
Another feature of the Mt. Rainier standard is background formatting. In the background formatting, a user making a formatting request is notified of a formatting completion message after recording only a portion of the lead-in zone. The remaining portions are recorded with dummy data when there is no access from the user. After receiving the formatting completion message, the user can record or reproduce data on a random-access basis with respect to all the user data area on the disk.
Moreover, it is possible to take a disk out during the background formatting before the recording of all the disk area is completed. When a disk is ejected during the background formatting, it is necessary for the conventional drive to properly read the disk having only a partial formatting. To this end, dummy data is recorded on unrecorded areas intervening between recorded data. Further, the outermost address (i.e., the last written address LWA) recorded with user data or recorded by formatting is used as a start position from which a temporary STA (hereinafter referred to as a TSTA) is recorded, for the purpose of allowing the MRW driver to obtain defect management information. At the end, a temporary lead-out (hereinafter referred to as a TLO) is recorded, followed by the ejection of the disk.
A DVD+MRW disk, for which reallocation to the SA2 is made after a defect is found during the formatting operation, may be taken out. In such a case, a temporary SA2 (hereinafter referred to as a TSA2) is set aside from the LWA, and spared data is then copied to the SA2, followed by recording the TSTA and the TLO. This is done for the purpose of shortening a time required for the ejection of the disk. That is, since the SA2 in DVD+MRW is located at the outermost circumference of the user data area, the process of inserting dummy data into the unrecorded areas up to the SA2 is omitted for the purpose of time saving. The TSA2 is a temporary spare area for use by the conventional drive to read the reallocated data. The size of the TSA2 is a sum of all the areas used for the spare purpose in the SA2.
(3) Example
FIGS. 7A and 7B are illustrative drawings showing the recording format of CD-MRW and DVD+MRW. FIG. 7A illustrates the recording format of CD-MRW, and FIG. 7B is the recording format of DVD+MRW.
Both CD-MRW and DVD+MRW are divided into a lead-in zone, a data zone, and a lead-out zone.
An MTA (main table area) is provided in the lead-in zone.
A GAA (general application area), an SA (spare area), a DA (data area), and an STA (secondary table area) are provided in the data zone. In the Mt. Rainier format, defect management information and information about the formatting status are recorded on the MTA and STA. The STA is a copy of what is stored in the MTA, and is situated in the data zone. User data is recorded on the DA. If a defect is found in the DA during the recording of data, reallocation to the SA is carried out. Further, the GAA stores information for use by an MRW driver to identify a MRW disk when a MRW disk is inserted into a conventional drive.
In this manner, MRW arranges an STA as a defect management area and an SA as a spare area in the data zone which is accessible by a conventional drive, thereby providing for the conventional drive to read the spare area.
The difference between CD-MRW and DVD+MRW resides in the arrangement of SA areas. CD-MRW disperses the SAs and the DAs sparsely as shown in FIG. 7A, whereas DVD+MRW arranges the SA1 at the innermost circumference of the data zone and the SA2 at the outermost circumference as shown in FIG. 7B. As a result, the DAs which record user data are contiguous.
FIGS. 8A and 8B are illustrative drawings showing the way CD-MRW and DVD+MRW are partially formatted. FIG. 8A illustrates the recording format of CD-MRW, and FIG. 8B is the recording format of DVD+MRW.
In CD-MRW, a TSTA (temporary secondary table area) is recorded following a user-recorded area or an area recorded by formatting with dummy data, and a TLO (temporary lead-out) is added. MTA information is copied to the TSTA, storing defect management information and information about formatting status. An MRW driver refers to the TSTA to acquire spare information. Since SAs are sparsely dispersed in CD-MRW, a defect that is detected in an i-th DA area during the background formatting is generally replaced by an i-th SA area.
In the case of DVD+MRW, on the other hand, spare areas exist only in the SA1 and the SA2. The SA2 may thus be used during the background formatting. If the SA2 is used, it is necessary to insert dummy data all the way from the position where formatting is done to the position of the SA2 so as to allow a conventional drive to read the data reallocated to the SA2. Since the SA2 is situated at the very end of the user data area, however, a disk cannot be taken out until formatting is complete if the SA2 is used as a replacement. In order to avoid this in DVD+MRW, as shown in FIG. 8B, data spared by (i.e., reallocated to) the SA2 is copied to the TSA2 (temporary SA2) following the formatted area. The disk is then ejected after recording the TSTA and the TLO following the TSA2.
In FIGS. 8A and 8B, “De-iced” represents areas where data is recorded. That is, “iced” indicates unrecorded areas, and “De-iced” means eliminating unrecorded areas.
(4) Art Disclosed in Publication
Japanese Patent Application Publication No. 10-021552 discloses an information recording apparatus that records spared data on the user data area. This information recording apparatus sets aside a portion of the user data area as a spare area if a large number of defect areas may exist depending on the conditions of the disk. The set-aside portion of the user data area will then be used as a spare area.
When the Mt. Rainier standard is employed, adding data to a partially formatted DVD+MRW gives rise to the following problems. FIGS. 9A through 9D are illustrative drawings for explaining problems that occur in DVD+MRW.
FIGS. 9A through 9D illustrate a case in which the updating of a TSA2 becomes necessary in DVD+MRW. FIG. 9A shows a partially formatted DVD+MRW. In FIG. 9A, data spared by (i.e., reallocated to) the SA2 is copied to a TSA2 following the formatted area, followed by the recorded TSTA and TLO.
(1) First Problem
Since the TSA2 resides in the user data area, as illustrated in FIG. 9B, there may be a case in which the TSA2 is overwritten by user data.
Here, a drive is configured to resume background formatting if the TSTA and the TLO, which exist in the user data area, are similarly overwritten by user data. Once the formatting resumes, a TSA2, a TSTA, and a TLO will again be recorded from the new LWA at the time of disk discharge. This prevents these areas from being destroyed by the overwriting user data.
However, no consideration is given to the fact that a TSA2 may be overwritten by user data. When a TSA2 is overwritten by user data, therefore, the TSA2 will not be rerecorded by the resumed background formatting or the like. Because of this, if a TSA2 is overwritten by user data as illustrated in FIG. 9B, the TSA2 will be left overwritten. When a disk having a TSA2 overwritten by user data is inserted into a conventional drive, the drive gives incorrect spare data to the user. Namely, when a TSA2 is overwritten by user data during the process of adding user data to a partially formatted disk, the TSA2 will no longer correctly represent the information of the SA2. If such a disk is inserted in a conventional drive, incorrect information will be given to a user.
(2) Second Problem
There may be a case in which a user wishes to store data in an area replaced by the SA2. In this case, as shown FIG. 9C, the data in the SA2 is updated.
While the TSA2 is provided for a conventional drive to read reallocated data, an MRW drive accesses the SA2 to record data on the SA2. As a result, the SA2 and the TSA2 end up storing different data.
In this manner, the SA2 may be updated during the process of adding user data to a partially formatted disk, resulting in a situation where the TSA2 does not correctly reflect data in the SA2. If such a disk is inserted into a conventional drive, incorrect information will be given to a user.
(3) Third Problem
A problem may also arise when a new defect is found during the recording of user data.
As previously described, the size of a TSA2 is only as big as a sum of all the areas actually used for replacement in the SA2. As shown in FIG. 9D, thus, a problem may be encountered in that there are no more areas for recording data that are newly found to be spared.
Accordingly, there is a need for a scheme by which a temporary spare area (e.g., a TSA2) correctly reflect data stored in the spare area (e.g., the SA2) even if a user records data in the temporary spare area in a recording medium such as a partially formatted DVD+MRW.
Further, there is a need for a scheme by which a temporary spare area (e.g., a TSA2) correctly reflect data stored in the spare area (e.g., the SA2) even if the temporary spare area or the spare area is overwritten in a recording medium such as a partially formatted DVD+MRW.